On 23/09/10 1:47 -0700, Eric W. Biederman wrote:
>
> Implementing file descriptors for the network namespace is simple and
> straight forward.
>
> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
[...]
> diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
> index c988e68..581a088 100644
> --- a/net/core/net_namespace.c
> +++ b/net/core/net_namespace.c
> @@ -571,3 +571,33 @@ void unregister_pernet_device(struct pernet_operations *ops)
> mutex_unlock(&net_mutex);
> }
> EXPORT_SYMBOL_GPL(unregister_pernet_device);
> +
> +#ifdef CONFIG_NET_NS
> +static void *netns_get(struct task_struct *task)
> +{
> + struct net *net;
> + rcu_read_lock();
> + net = get_net(task->nsproxy->net_ns);
task could be exiting, so task->nsproxy could be NULL, right?
Maybe make proc_ns_instantiate() rcu_dereference task->nsproxy, check for it
being not NULL, and pass task->nsproxy to ns_ops->get()?
That could be an issue for the user namespace since it is not in nsproxy, but
maybe no reasonable usage of ns_ops with user namespaces is envisioned.
Otherwise, checking that task is alive with RCU locked in proc_ns_instantiate() should be enough to be
rely on task->cred when calling ns_ops->get().
Thanks,
Louis
> + rcu_read_unlock();
> + return net;
> +}
> +
> +static void netns_put(void *ns)
> +{
> + put_net(ns);
> +}
> +
> +static int netns_install(struct nsproxy *nsproxy, void *ns)
> +{
> + put_net(nsproxy->net_ns);
> + nsproxy->net_ns = get_net(ns);
> + return 0;
> +}
> +
> +const struct proc_ns_operations netns_operations = {
> + .name = PROC_NSNAME("net"),
> + .get = netns_get,
> + .put = netns_put,
> + .install = netns_install,
> +};
> +#endif
> --
> 1.6.5.2.143.g8cc62
>
> --
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--
Dr Louis Rilling Kerlabs
Skype: louis.rilling Batiment Germanium
Phone: (+33|0) 6 80 89 08 23 80 avenue des Buttes de Coesmes
http://www.kerlabs.com/ 35700 Rennes
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